C++ FAQ Celebrating Twenty-One Years of the C++ FAQ!!!
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Section 33:
[33.3] Why do I keep getting compile errors (type mismatch) when I try to use a member function as an interrupt service routine?

This is a special case of the previous two questions, therefore read the previous two answers first.

Non-static member functions have a hidden parameter that corresponds to the this pointer. The this pointer points to the instance data for the object. The interrupt hardware/firmware in the system is not capable of providing the this pointer argument. You must use "normal" functions (non class members) or static member functions as interrupt service routines.

One possible solution is to use a static member as the interrupt service routine and have that function look somewhere to find the instance/member pair that should be called on interrupt. Thus the effect is that a member function is invoked on an interrupt, but for technical reasons you need to call an intermediate function first.